The tipping level for Twitter's level of popularity was the 2007 South by Southwest Interactive (SXSWi) convention. It experienced 400,000 tweets posted for each quarter in 2007. This grew to one hundred million tweets posted for every quarter in 2008. In February 2010, Twitter buyers had been sending 50 million tweets for each day. Work on the task commenced on March 21, 2006, when Dorsey released the initially Twitter concept at 12:50 p.m.